1. Field of the Invention
The present invention relates to a mobile terminal, also called a wireless terminal, and more particularly to a mobile terminal for automatically managing a country code during roaming, and a method for storing and finding a phone number using the mobile terminal
2. Description of the Related Art
Typically, a GSM (Global System for Mobile communication) is a digital mobile phone system widely used in Europe and other countries in recent times. The GSM is a variant of TDMA (Time Division Multiple Access), and is one of the three most widely used wireless telephony systems: the TDMA system, the CDMA (Code Division Multiple Access) system, and the GSM system. A GSM enables a user who travels abroad to continuously use his or her mobile phone anywhere he or she wishes because many international GSM network enterprisers have entered into roaming agreements with each other.
Conventionally, in the case where a user of a GSM-based mobile service moves from one country to another country and thus a roaming process between such countries is performed, in order to select a phone number previously registered in a mobile terminal and to use the selected phone number to make a phone call to a receiving party, the user must append a corresponding country code to the registered phone number prior to roaming. Also, the user who is roaming from one country to another country must append a country code of an original country to the phone number registered on a PLMN (Public Land Mobile Network) of the original country, in order for the user's phone number as registered on the PLMN to be stored in his or her mobile terminal.
FIG. 1 is an exemplary view illustrating a conceptual diagram wherein an international roaming process occurs on a PLMN service network. Referring to FIG. 1, in the case where a mobile terminal 10 of a subscriber registered in a MSC (Mobile Switching Center) 30 of a PLMN B service having a country code of ‘0033’ roams within a MSC's 20 area of a PLMN A service having a country code of ‘0044’, a user of the mobile terminal 10 must append a country code of ‘0033” to a prestored phone number to make a phone call to the prestored phone number. Unless the user appends the country code of ‘0033’ to the prestored phone number, there may occur an erroneous phone call to another party registered to the PLMN A service having the country code of ‘0044’. For example, in the case where the mobile terminal 10 previously stores a phone number of ‘123-4567’ therein, and a user of the mobile terminal 10 selects only the phone number of 123-4567 without appending an appropriate country code to the phone number of ‘123-4567’, the PLMN A service MSC 20 makes a phone call to a wrong phone number of ‘0044-123-4567’ instead of a correct phone number of ‘0033-123-4567’.
Conversely, in the case where the PLMN B service subscriber attempts to store in the mobile terminal 10 a phone number of a user registered to the PLMN A service in an area of the PLMN A service MSC 20, the subscriber must append a country code of ‘0044’ corresponding to the PLMN A service to the user's phone number. Otherwise, the mobile terminal 10 recognizes the user's phone number as a phone number of a subscriber registered to the PLMN B service.
In this manner, conventionally, in the case where a user of such a PLMN service moves from one country to another country and thus there occurs a roaming process between countries, he or she must append an additional country code to his or her phone number in order to make a phone call to a called party or store any phone number in the mobile terminal, resulting in a user's inconvenience.